Guide

How to get PDF headings and bookmarks right

Heading levels are how a screen-reader user navigates a long document. Skipped levels, fake headings and empty bookmarks, and how to fix each.

About 11 minutes · moderate

Why levels matter more in a PDF than on the web

A screen-reader user in a long document does not read it. They navigate it: H jumps to the next heading, 1 to the next level-1 heading, and the heading list gives them the document’s shape in one view.

On a web page there is other structure to fall back on — landmarks, links, a nav bar. A PDF has almost none of that. Headings and bookmarks are essentially the entire navigation surface, which makes a broken hierarchy more disabling here than anywhere else.

The three failures

Fake headings

Text that looks like a heading — bold, larger, a different colour — and is tagged P. Sighted readers see a heading. A screen-reader user gets an ordinary paragraph, and the document has no structure at all in their heading list.

This is the most common of the three because it is what happens when a document is written with direct formatting instead of styles. Word’s Heading 1 becomes H1 in the export; 16pt bold Calibri becomes P.

Find it: open the Tags panel, and click through every element that looks like a heading on the page. Or faster — open the document in PAC and look at the structure outline. If it is flat, they are all paragraphs.

Fix it: in Acrobat’s Tags panel, right-click the element → Properties → Type → Heading Level 1 (or 2, 3…). For more than a handful, fix it in the source document and re-export, which is faster and produces a better file.

Skipped levels

H1, then H3. This is condition 14-003, and the effect is that a user navigating by level 2 skips content entirely — they have no way of knowing the H3s exist under that H1.

It usually comes from visual design: the designer wanted a smaller heading, so they picked the style that looked right rather than the level that was right. The fix is to correct the level and restyle it, not to leave the level wrong.

Find it: Acrobat’s accessibility checker reports this one reliably, as do veraPDF and PAC. It is a genuinely machine-decidable condition and every checker gets it right.

Fix it: change the Type in the Tags panel. Then check what follows — a fixed skip often reveals another one below it, because these tend to come in runs.

Headings that are not headings

The reverse problem: a paragraph tagged H2 because a template applied a heading style to a caption, a pull-quote or a table cell. The heading list fills with fragments and stops being useful.

A special case worth naming: an entire page of a table of contents tagged as headings. It happens when a TOC is generated from heading styles and the styles come across. The result is a heading list that is a duplicate of itself.

Fix it: retype those elements as P, or Caption, or whatever they actually are.

What a correct hierarchy looks like

H1  Annual Report 2025
  H2  Financial summary
    H3  Revenue
    H3  Expenditure
  H2  Operations
    H3  Northern district
      H4  Staffing
    H3  Southern district
  H2  Appendices

Levels descend by one and may jump back up by any amount. H4 followed by H2 is correct — that is closing two sections. H2 followed by H4 is not.

Bookmarks

Bookmarks are a separate structure: an outline tree hanging off the document catalog, independent of the tag tree.

Generate them from headings, not by hand. In Word, tick Create bookmarks using: Headings in the PDF export options. In InDesign, generate a TOC and tick Create PDF Bookmarks. In Acrobat, View → Show/Hide → Navigation Panes → Bookmarks, then the panel menu → New Bookmarks from Structure, which reads your tag tree.

That last one is worth knowing about. If your headings are correct, it produces a correct outline in one click, and if it produces a strange outline, that is diagnostic — your headings are wrong.

Three things that break bookmarks:

• Bookmarks pointing at the wrong page. Usually because pages were inserted or deleted after generation. Regenerate rather than repairing individually.
• Empty or duplicate labels. “Untitled” entries, or twelve entries all called “Introduction”. A bookmark’s label is the only thing a user has to choose by.
• A flat outline for a structured document. Forty top-level bookmarks with no nesting is a list, not an outline. Nest them to match the heading hierarchy.

Verify it in ninety seconds

Open the Bookmarks panel and read the outline. Does it look like the document’s table of contents? If you cannot tell what the document is about from it, the headings are wrong somewhere upstream.

Then, if you have PAC, open the structure view and read the heading list on its own. That list is the experience of navigating the document. If it reads as an outline, you are done. If it reads as fragments — captions, half-sentences, page numbers — there is fake-heading work to do.

Related failure conditions

• 14-001 Headings are not tagged Text that is visually a heading — larger, bolder, isolated — is tagged as a paragraph. The document has no navigable outline.
• 14-003 Numbered heading levels in descending sequence are skipped The heading hierarchy jumps a level going down — H1 straight to H3. Going back up any number of levels is fine; going down must be one level at a time.
• 09-001 Tags are not in logical reading order The order of elements in the structure tree does not match the order a human would read the page. This is the single most common substantive defect in tagged PDFs and the one Acrobat's own tooling handles worst.
• 28-005 A form field has neither a TU entry nor an alternative description The /TU tooltip is the accessible name of a PDF form field. Without it the field has no name at all — the visible label printed next to it is not connected to the control.

Last updated 2026-09-10 .